The specific aims of the study are to: (1) evaluate the safety and describe the reactogenicity of two candidate HIV-1 vaccines administered simultaneously: ALVAC vCP205 and SF-2 rgp 120; (2) evaluate the humoral and cellular immunogenicity of this combination of vaccines; (3) compare reactogenicity and immunogenicity of this combination of two candidate vaccines in individuals at lower risk and higher risk of HIV-1 infection; (4) assess the feasibility of conducting preventive HIV-1 vaccine efficacy trials in high risk populations through the existing HIVNET structure, including the ability to recruit and retain a diverse cohort of high risk individuals into preventive HIV-1 vaccine trials; and (5) evaluate potential behavioral and social risks to study participants in preventive HIV-1 vaccine trials.